mirror of
https://github.com/servo/servo.git
synced 2025-08-03 04:30:10 +01:00
style: Make static atom pointers constexpr
.
This saves one word per static atom, per process. The `nsGkAtoms` change is only a small part of this commit. In regen_atoms.py: - There is now only one link name per platform: nsGkAtoms::sAtoms[]. - But there is a new constant per atom, giving the index into nsGkAtoms::sAtoms[]. - And the `atom!` macro for each atom indexes into nsGkAtoms::sAtoms[] using the index constant. - A couple of `*mut` pointers are now `*const`. Elsewhere, the `(nsStaticAtom*)` casts within the `AppendElement()` calls are necessary to avoid link errors, presumably due to some template instantiation wrinkle. Bug: 1449787 Reviewed-by: froydnj,emilio
This commit is contained in:
parent
c276c8a341
commit
0d5d5a9c82
2 changed files with 30 additions and 46 deletions
|
@ -20,21 +20,6 @@ import build
|
|||
PATTERN = re.compile('^GK_ATOM\(([^,]*),[^"]*"([^"]*)",\s*(0x[0-9a-f]+),\s*([^,]*),\s*([^)]*)\)',
|
||||
re.MULTILINE)
|
||||
FILE = "include/nsGkAtomList.h"
|
||||
CLASS = "nsGkAtoms"
|
||||
|
||||
|
||||
def gnu_symbolify(ident):
|
||||
return "_ZN{}{}{}{}E".format(len(CLASS), CLASS, len(ident), ident)
|
||||
|
||||
|
||||
def msvc64_symbolify(ident, ty):
|
||||
return "?{}@{}@@2PEAV{}@@EA".format(ident, CLASS, ty)
|
||||
|
||||
|
||||
def msvc32_symbolify(ident, ty):
|
||||
# Prepend "\x01" to avoid LLVM prefixing the mangled name with "_".
|
||||
# See https://github.com/rust-lang/rust/issues/36097
|
||||
return "\\x01?{}@{}@@2PAV{}@@A".format(ident, CLASS, ty)
|
||||
|
||||
|
||||
def map_atom(ident):
|
||||
|
@ -46,7 +31,7 @@ def map_atom(ident):
|
|||
|
||||
class Atom:
|
||||
def __init__(self, ident, value, hash, ty, atom_type):
|
||||
self.ident = "{}_{}".format(CLASS, ident)
|
||||
self.ident = "nsGkAtoms_{}".format(ident)
|
||||
self.original_ident = ident
|
||||
self.value = value
|
||||
self.hash = hash
|
||||
|
@ -60,15 +45,6 @@ class Atom:
|
|||
if self.is_anon_box():
|
||||
assert self.is_inheriting_anon_box() or self.is_non_inheriting_anon_box()
|
||||
|
||||
def gnu_symbol(self):
|
||||
return gnu_symbolify(self.original_ident)
|
||||
|
||||
def msvc32_symbol(self):
|
||||
return msvc32_symbolify(self.original_ident, self.ty)
|
||||
|
||||
def msvc64_symbol(self):
|
||||
return msvc64_symbolify(self.original_ident, self.ty)
|
||||
|
||||
def type(self):
|
||||
return self.ty
|
||||
|
||||
|
@ -148,19 +124,18 @@ PRELUDE = '''
|
|||
IMPORTS = '''
|
||||
use gecko_bindings::structs::nsStaticAtom;
|
||||
use string_cache::Atom;
|
||||
|
||||
'''
|
||||
|
||||
UNSAFE_STATIC = '''
|
||||
#[inline(always)]
|
||||
pub unsafe fn atom_from_static(ptr: *mut nsStaticAtom) -> Atom {
|
||||
pub unsafe fn atom_from_static(ptr: *const nsStaticAtom) -> Atom {
|
||||
Atom::from_static(ptr)
|
||||
}
|
||||
'''
|
||||
|
||||
ATOM_TEMPLATE = '''
|
||||
SATOMS_TEMPLATE = '''
|
||||
#[link_name = \"{link_name}\"]
|
||||
pub static {name}: *mut {type};
|
||||
pub static nsGkAtoms_sAtoms: *const nsStaticAtom;
|
||||
'''[1:]
|
||||
|
||||
CFG_IF_TEMPLATE = '''
|
||||
|
@ -178,14 +153,19 @@ cfg_if! {{
|
|||
{msvc32}\
|
||||
}}
|
||||
}}
|
||||
}}
|
||||
}}\n
|
||||
'''
|
||||
|
||||
CONST_TEMPLATE = '''
|
||||
pub const k_{name}: isize = {index};
|
||||
'''[1:]
|
||||
|
||||
RULE_TEMPLATE = '''
|
||||
("{atom}") =>
|
||||
{{{{
|
||||
use $crate::string_cache::atom_macro;
|
||||
#[allow(unsafe_code)] #[allow(unused_unsafe)]
|
||||
unsafe {{ $crate::string_cache::atom_macro::atom_from_static ($crate::string_cache::atom_macro::{name} as *mut _) }}
|
||||
unsafe {{ atom_macro::atom_from_static(atom_macro::nsGkAtoms_sAtoms.offset(atom_macro::k_{name})) }}
|
||||
}}}};
|
||||
'''[1:]
|
||||
|
||||
|
@ -196,28 +176,28 @@ macro_rules! atom {{
|
|||
}}
|
||||
'''
|
||||
|
||||
|
||||
def write_atom_macro(atoms, file_name):
|
||||
def get_symbols(func):
|
||||
return ''.join([ATOM_TEMPLATE.format(name=atom.ident,
|
||||
link_name=func(atom),
|
||||
type=atom.type()) for atom in atoms])
|
||||
|
||||
with FileAvoidWrite(file_name) as f:
|
||||
f.write(PRELUDE)
|
||||
f.write(IMPORTS)
|
||||
|
||||
for ty in sorted(set([atom.type() for atom in atoms])):
|
||||
if ty != "nsStaticAtom":
|
||||
f.write("pub enum {} {{}}\n".format(ty))
|
||||
|
||||
f.write(UNSAFE_STATIC)
|
||||
|
||||
gnu_symbols = get_symbols(Atom.gnu_symbol)
|
||||
msvc32_symbols = get_symbols(Atom.msvc32_symbol)
|
||||
msvc64_symbols = get_symbols(Atom.msvc64_symbol)
|
||||
gnu_name='_ZN9nsGkAtoms6sAtomsE'
|
||||
gnu_symbols = SATOMS_TEMPLATE.format(link_name=gnu_name)
|
||||
|
||||
# Prepend "\x01" to avoid LLVM prefixing the mangled name with "_".
|
||||
# See https://github.com/rust-lang/rust/issues/36097
|
||||
msvc32_name = '\\x01?sAtoms@nsGkAtoms@@0QBVnsStaticAtom@@B'
|
||||
msvc32_symbols = SATOMS_TEMPLATE.format(link_name=msvc32_name)
|
||||
|
||||
msvc64_name = '?sAtoms@nsGkAtoms@@0QEBVnsStaticAtom@@EB'
|
||||
msvc64_symbols = SATOMS_TEMPLATE.format(link_name=msvc64_name)
|
||||
|
||||
f.write(CFG_IF_TEMPLATE.format(gnu=gnu_symbols, msvc32=msvc32_symbols, msvc64=msvc64_symbols))
|
||||
|
||||
consts = [CONST_TEMPLATE.format(name=atom.ident, index=i) for (i, atom) in enumerate(atoms)]
|
||||
f.write('{}'.format(''.join(consts)))
|
||||
|
||||
macro_rules = [RULE_TEMPLATE.format(atom=atom.value, name=atom.ident) for atom in atoms]
|
||||
f.write(MACRO_TEMPLATE.format(body=''.join(macro_rules)))
|
||||
|
||||
|
|
|
@ -4,6 +4,10 @@
|
|||
|
||||
#![allow(unsafe_code)]
|
||||
|
||||
// This is needed for the constants in atom_macro.rs, because we have some
|
||||
// atoms whose names differ only by case, e.g. datetime and dateTime.
|
||||
#![allow(non_upper_case_globals)]
|
||||
|
||||
//! A drop-in replacement for string_cache, but backed by Gecko `nsAtom`s.
|
||||
|
||||
use gecko_bindings::bindings::Gecko_AddRefAtom;
|
||||
|
@ -280,7 +284,7 @@ impl Atom {
|
|||
/// that way, now we have sugar for is_static, creating atoms using
|
||||
/// Atom::from_raw should involve almost no overhead.
|
||||
#[inline]
|
||||
pub unsafe fn from_static(ptr: *mut nsStaticAtom) -> Self {
|
||||
pub unsafe fn from_static(ptr: *const nsStaticAtom) -> Self {
|
||||
let atom = Atom(ptr as *mut WeakAtom);
|
||||
debug_assert!(
|
||||
atom.is_static(),
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue